KTIV News 4 Sioux City IA: News, Weather and SportsFitness Level vs BMI: Which is more important?

For years we've been taught that keeping our BMI, or body mass index, at a good level means your healthy, but a new study says that may not the be the only determining factor. It suggests that your fitness level may play a bigger role in determining your overall health than that calculated number.

You workout, you watch what you eat, for the most part; but your BMI calculation still puts you just into the "overweight" category. "It's estimated that possibly two-thirds of the population in the U.S. falls into the category of either overweight or obese," said Dr. Mick Hurley. But for some of those people, being above normal for BMI may not be unhealthy.

The BMI, or body mass index, is calculated by dividing your weight in pounds by your height in inches. A normal range is from 18.5 to 25. 25 to 30 is overweight and above 30 is obese. But how much does that number matter? A study published in Circulation: Journal of the American Heart Association followed more than 14-thousand men with an average age of 44 for more than 11 years. Researchers tracked their BMI and fitness levels. "As it turned out, the level of fitness was more important than BMI," said Dr. Hurley. Researchers say maintaining or improving your fitness level can lower your risk of heart disease and stroke, more than making sure you're BMI is in the right range. Moral of the study, get your 30 to 60 minutes of moderate exercise at least 5 days a week. "You want to exercise to a level that you could continue to exercise and talk to someone who was exercising beside you, whether it's walking or jogging, but not exercise to a level that you wouldn't be able to comfortably sing," said Dr. Hurley. So let your doctor crunch the BMI numbers, and you just keep track of your workouts.

Dr. Hurley says make sure you include a warm-up and cool down with your workout. If you're just starting out, start small and work your way up. And he says to make sure you do plenty of cardio-vascular exercise like walking, biking and elliptical, but try to work in some weight-lifting a couple days a week.